1. Field of the Invention
This invention relates to a system for storing of printing products brought out from a printing machine and for transporting them to a further-treatment machine of the type, wherein the printing products are kept in a compressed state by external forces within a staple during storage and transport and wherein the forces are reduced before the further-treatment.
2. Description of the Prior Art
With the production of books, newspapers, and job-type printing products it is necessary after the printing process to combine the single folded sheets brought out from the printing machine to the end product, as, for example, by means of collecting stitching or stapling machines or collecting machines. It is known to store the part-products brought out from the folding apparatus of the printing machine in bunches or staples on pallets in an unsecured manner. This is the most commonly used procedure. Further, it is known to bind the bunches or staples between small boards and to store them in this form on a pallet.
Further, a system of the above-described type is known, with which the staple is compressed between clamps and is transported together with the clamps to the further-treatment machine by means of transport devices.
In the daily use the above manners of storing and transporting have considerable disadvantages. First, the known systems can hardly be automated, since the compressed or uncompressed sheet staples stored on the pallet can only be positioned on said transport pallets unsufficiently. During the loading of the further treatment machines with the sheet staples manual work cannot be avoided, so that the further treatment is extensive with respect to manpower. Naturally, the same holds true for sheet staples supported on the transport pallets and being clamped by the clamps.
During the loading of the further treatment-machines with the staples not only the transport pallets are set free, but also the several auxiliary means, like boards, latching material and clamps, which are not connected to the transport pallets. Besides the pallets the auxiliary means, which may be still used again, have to be brought back to the folding apparatus of the printing machine and the auxiliary material which cannot be used again, has to be removed from the further treatment machines. The auxiliary material, which cannot be used again, leads to considerable additional costs.
Sheets, which are compressed or eventually only secured by the boards, are stacked one above the other on the transport pallets and care has to be taken that the part-staples are arranged one above the other in a brick-like manner to achieve at least a minimum of stability on said pallet. Normally, the pallets are transported by means of fork-lifts, so that a jerky and impact-like action on the staples cannot be avoided always.
A further disadvantage of the simple stacking of the part-staples one upon the other on said transport pallets resides in the fact that the lower layers of part-products are compressed to a considerably greater extent than the upper layers. This leads to a different forming of the folds of the sheets with the upper and the lower layers, respectively. The different state of folding, however, causes stopping actions in the further-treatment machines. The different folding state is a crucial obstacle in the production chain: printing machine-final product.
With the storing of products on pallets normally a plurality of pallets is stacked one upon the other due to reasons of the space available, the lower part of the upper pallet, however, presses on the layer of sheets on the pallet arranged under the upper pallet and may cause considerable damages. The use of special intermediate protection boards has not proved to be successful, since these boards would constitute a further flow of material. On the other hand, the damages caused by the feet of the upper pallet on the other layer of sheets on the lower pallet are often of such an extent that these sheets have to be sorted manually before the products stored on the lower transport pallet are loaded into a further-treatment machine. Even if a damaged sheet has been accepted by one treatment machine, this sheet may still cause a stopping action in another treatment machine, if the sheet or part-product treated in one machine has to be further treated in another treatment machine.